Trends in Neurosciences
December 10, 2019
Tim Bayne, Anil K. Seth, Marcello Massimini
146 citations
Consciousness might persist in brain tissue that is fully causally isolated from the body and environment, forming an 'island of awareness'—a conscious state neither shaped by sensory input nor able to produce motor output. This opinion paper examines three potential cases: ex cranio brains (brains kept alive outside the body), the disconnected hemisphere after hemispherotomy surgery, and cerebral organoids (lab-grown brain tissue). The authors discuss methods for detecting consciousness in such disconnected brains, noting that current detection tools rely on sensory or motor interaction and may not apply. They argue that discovering islands of awareness would have profound ethical and legal implications and would challenge theories holding that consciousness requires embodiment or interaction with the world.
Trends in Neurosciences
December 21, 2020
Neil K. Savalia, Ling-Xiao Shao, Alex C. Kwan
110 citations
Ketamine and serotonergic psychedelics like psilocybin both relieve depression and promote neural plasticity, despite targeting different molecular receptors. This opinion article proposes a conceptual framework suggesting their actions converge at the dendrites, where they both enhance and suppress membrane excitability. Mismatches in these opposing effects may explain differences in cell-type and region selectivity, the compounds' moderate range of effects and toxicity, and their plasticity-promoting capacities.
Trends in Neurosciences
May 31, 2024
Andrea I. Luppi, Fernando E. Rosas, Pedro A. M. Mediano et al.
23 citations
Unconsciousness increases the coupling between brain structure and function across scales, while psychedelics may decouple brain function from structure. Anaesthetics, psychedelics, and disorders of consciousness can produce similar reconfigurations along the brain's unimodal-transmodal functional axis. Decomposing brain function into fundamental constituents of time, space, and information has driven recent advances in understanding consciousness and the brain's functional organisation. Computational modelling offers a path toward mechanistic integration, and decomposition approaches may help translate discoveries across species.
Trends in Neurosciences
June 1, 2023
Jaan Aru, M. Larkum, J. Shine
Claims that large language models may soon be conscious are difficult to defend from a neuroscience perspective. The inputs to these models lack the embodied, embedded information content that characterizes sensory contact with the world. Present-day AI architectures also miss key features of the thalamocortical system linked to conscious awareness in mammals. Furthermore, the evolutionary and developmental trajectories that produced living conscious organisms have no parallels in current artificial systems. The existence of living organisms depends on actions and survival, which are linked to multi-level cellular, inter-cellular, and organismal processes that culminate in agency and consciousness.